<html>
<body>
<h2>Hello World!</h2>
<div>
    <form method="post" enctype="multipart/form-data" action="/demo/upload">
        <input placeholder="请选择上传的文件" type="file" name="file"/>
        <input type="submit" value="上传">
    </form>
</div>
</body>
</html>
